Atomically dispersed ruthenium in carbon aerogels as effective catalysts for pH-universal hydrogen evolution reaction

Development of cost-effective catalysts for hydrogen evolution reaction (HER) plays a significant role in scalable production of hydrogen. Herein, carbon aerogels doped with atomically isolated Ru are produced pyrolytically from biomass hydrogels and exhibit a remarkable performance in HER within a broad range of solution pH, due to the formation of abundant RuN_x moieties. At the current density of 10 mA cm⁻², the optimal sample (NCAG/Ru-3) exhibits an ultralow overpotential of merely −4 mV in 1.0 M KOH, −45 mV in 1.0 M phosphate buffer solution and −65 mV in 0.5 M H₂SO₄, with the respective mass activity 44, 16 and 6 times that of commercial Pt/C benchmark. The excellent performance is also manifested in full water splitting. Theoretical calculations suggest that the high activity arise from the RuN_x sites at the zigzag edges and nanowrinkles. These results underscore the unique quality of carbon aerogel-based single atom catalysts in electrochemical energy technologies.